Air foil conveyor

ABSTRACT

A common plenum supplies air to a plurality of parallel air foil nozzles disposed in tandem and operative upon a sheet of material adjacent to the nozzle to convey the sheet relative thereto.

United States Patent Overly, William F. et a1.

1451 Dec. 12, 1972 [54] AIR FOIL CONVEYOR [72] Inventors: William F. Overly, Winneconne; Kenneth J. Pagel, Neenah, both of Wis.

Assignee: Overly, Inc., Neenah, Wis.

Filed: March 16, 1970 Appl. No.: 19,687

US. Cl ..226/97 Int. Cl. ..B65h 17/32 Field of Search ..226/7, 97, 91; 34/156, 160,

[56] References Cited UNITED STATES PATENTS 1,605,067 11/1926 Read ..34/120x Gautreau ..34/156 X Allander ..34/156 Allander ..226/91 X Allander ..226/97 Petersson ..226/97 Fraser ..34/156 Primary Examiner-Richard A. Schacher Attorney-Andrus, Sceales, Starke & Sawall ABSTRACT A common plenum supplies air to a plurality of parallel air foil nozzles disposed in tandem and operative upon a sheet of material adjacent to the nozzle to convey the sheet relative thereto.

5 Claims, 5 Drawing Figures PATENTEDuEc 12 1912 3 705,676

sum 2 0F 2 INVENTORS WM. F OVERLY KENNETH J. PAGEL A/ Z ZW/ZM Attorneys AIR FOIL CONVEYOR EARLIER APPLICATION Reference is made to application Ser. No. 817,834 filed Apr. 21, 1969, and now U.S. Pat. No. 3,587,177 and which shows an air foil nozzle of the type employed by applicants.

BACKGROUND OF INVENTION The invention relates to an air foil conveyor which finds its principle use in the conveyance of materials as by air without other physical engagement therewith.

The invention has been proposed particularly for use in the paper making industry, to convey paper trim from a rewinder to a broke pulper, and also to convey the initial narrow ribbon of paper between rolls during threading of a paper machine.

Heretofore, the paper industry has lacked any satisfactory means of conveying paper trim to a pulper, and of conveying a narrow ribbon of raw paper in threading a paper machine. Previous means have always involved touching the material physically often resulting in breaks or plugging.

Trim material is hardly more than a wet conglomerate mass of pulp having practically no strength and quite susceptible to clogging most types of conveyors.

Likewise the threading ribbon of paper in a paper machine is often very delicate and since its speed toward the end is usually up to 5,000 feet per-minute, the directing of it into each successive roll from the preceding one becomes a feat of substantial dexterity.

The present invention provides a conveyor unit which can be positioned as desired in multiples to provide air jets disposed in tandem adjacent the material to be conveyed and effecting an air borne conveyance of the material in the direction desired without manual contact and without endangering the machine operator.

SUMMARY OF INVENTION The air foil conveyor of the present invention is made up of one or more conveyor units providing the total length of conveyor needed and having a width corresponding generally somewhat in excess of the width of the material to be conveyed.

It is convenient to make the conveyor in units of a standard length, and if the conveyor needs greater length additional units may be placed end to end.

Each unit comprises a plenum chamber having a series of longitudinally spaced parallel air foil nozzles in one surface thereof. The unit may be generally planular, or it may be curved in its length, depending upon the desired path of conveyance.

An air supply duct is connected to the back or side of the plenum chamber and feeds air thereto from a suitable fan at a rate sufficient to make the air foil discharge nozzles operative.

Each air foil nozzle is of the type referred to in the foregoing application Ser. No. 817,834 filed by the present applicants on Apr. 21, 1969.

More specifically each air foil nozzle consists of an outwardly curved surface extending transversely across the face of the plenum chamber and which at its outermost extremity merges into a generally flat surface extending to the next air foil nozzle in the direction of conveyance of the material, and an angularly disposed foil plate generally tangential to the curved foil surface but spaced therefrom just sufficiently to provide the desired nozzle opening therebetween.

The foil plate for the first nozzle is preferably formed from the end of the plenum chamber.

The foil plate for each successive nozzle is preferably integrally formed as one terminal edge of the flat surface of the preceding nozzle.

The terminal edge of the flat surface for the last nozzle preferably merges with the corresponding end of the plenum chamber.

BRIEF DESCRIPTION OF DRAWINGS The invention is illustrated drawings in which:

FIG. 1 is a longitudinal central section of a conveyor unit having four nozzles;

FIG. 2 is a top plan view of the unit of FIG. 1;

FIG. 3 is a schematic top plan view showing use of a plurality of nozzle units for conveying trim; 7 FIG. 4 is a schematic side elevation showing use of a plurality of nozzle units for threading a roll in a paper machine; and

FIG. 5 is a detail section schematically showing the arrangement of a plurality of units in a curved conveyor path in which a portion of the path may be substantially vertical.

in the accompanying DESCRIPTION OF THE EMBODIMENTS Referring to the drawings, FIGS. 1 and 2 illustrate a conveyor unit I of convenient size having four air foil nozzles 2 disposed in tandem along the length of one face of a plenum chamber 3.

Each nozzle 2 is formed by foil surface 4 extending transversely across the chamber 3 to provide a portionof the face thereof, and which surface has one edge portion 5 curved on a suitable radius for approximately with its outermost portion merging with a generally flat portion 6 extending forwardly to the next nozzle.

Cooperating with portion 5 of foil surface 4 is a foil plate 7 disposed generally tangential of portion 5 but spaced therefrom to provide a narrow slit 8 constituting the nozzle discharge opening for air from the plenum chamber 3.

The foil plate 7 extends across the face of the plenum chamber. The plate 7 at the end of the plenum chamber is preferably integral with the end wall 9 of the chamber. The plates 7 for the successive nozzles are preferably formed integral with the terminal edges of the generally flat portions 6 of the preceding foil surfaces 4.

The terminal edge of portion 6 of the last foil surface 4 preferably is integral with the end 10 of the plenum chamber 3.

The plenum chamber 3 is generally rectangular in cross section and is supplied with air through a duct 11 opening into the chamber on the back side 12.

Referring to FIG. 3 of the drawing, there is schematically shown a paper slitter 13 followed by a rewind roll 14.

The web 15 of wet paper is passing through the slitter 12 to the rewind roll 14 and as it goes through the slitter a waste portion or trim 16 is slit from the web before the latter enters the rewind roll.

The trim 16 is often wet pulpy material which has to be delivered back into the pulper for re-use. It is considered one of the most difficult materials to convey since it tends to clog conveyors heretofore attempted. The problem can be appreciated when it is pointed out that the web 15 is often moving at several thousand feet per minute.

In the illustration several conveyor units 1 of the present invention are disposed end to end to carry the trim air borne from the slitter 13 back to the pulper, not shown, which may be at some distance from the rewinder.

.Referring to FIG. 4, which shows a typical portion of a threading operation utilizing the present invention in a paper machine, the ribbon 17 of paper is being floated from a pair of rolls 18 horizontally to a succeeding pair of rolls l9vby means of several units 1 of the present conveyor and which may guide the ribbon over intermediate rolls 20 and 21 with a vertical course intermediate the latter rolls.

Referring to FIG. 5, the conveying of either the trim or the threading ribbon is shown in a curved path from a horizontal to a vertical. In this embodiment of the invention the units 22 are constructed the same as units 1 except that they are curved from end to end to provide the desired change in the conveyor path or direction. If greater force is needed on the material for lifting purposes it is possible to provide conveyor units 22 on both sides of the material as shown and to at least partially block off the escape of air at the side edges by extending the sides of plenum chamber 3 to form baffle plates 23 arranged to confine the flow of air more fully to the direction of material movement.

The flow speed of air may be as desired to effect the necessary conveyance of the material and the volume of air needed depends upon the spacing of the faces of the units from the material. In general it will be desirable to space the units one or more inches from the unit and the material being conveyed, each said slot discharging air generally tangential to a curved surface of said nozzle which merges with a flat surface disposed in a plane parallel to the general plane of travel of the material and extending continuously from one nozzle slot to the next for controlling the flow of air along the surface of the material from air foil nozzle to air foil nozzle of said unit.

2. The conveyor of claim 1 employing a plurality of said conveyor units disposed end to end.

3. The conveyor of claim 1 employing a plurality of said conveyor units facing each other and disposed generally parallel with the material being conveyed therebetween.

4. The construction of claim 3 in which the conveyor units are curved longitudinally to provide a curvalinear path for the material.

5. The conveyor of claim 1 in which the plenum unit is curved longitudinally to effect a change in direction for the conveyor. 

1. An air foil conveyor for sheet or web-like material generally required to be air borne, comprising a plenum unit of a width corresponding to the width of the material to be conveyed and of a substantially greater length and having a plurality of air foil nozzles providing discharge orifices in the form of generally parallel slots extending across the unit for substantially the full width thereof and spaced in tandem in the face thereof to direct a high velocity air stream longitudinally thereof in the region between the face of the unit and the material being conveyed, each said slot discharging air generally tangential to a curved surface of said nozzle which merges with a flat surface disposed in a plane parallel to the general plane of travel of the material and extending continuously from one nozzle slot to the next for controlling the flow of air along the surface of the material from air foil nozzle to air foil nozzle of said unit.
 2. The conveyor of claim 1 employing a plurality of said conveyor units disposed end to end.
 3. The conveyor of claim 1 employing a plurality of said conveyor units facing each other and disposed generally parallel with the material being conveyed therebetween.
 4. The construction of claim 3 in which the conveyor units are curved longitudinally to provide a curvalinear path for the material.
 5. The conveyor of claim 1 in which the plenum unit is curved longitudinally to effect a change in direction for the conveyor. 